How is it that we horses are so much better at surviving the cold than humans? To tell the truth, our bodies are designed to deal with temperatures well below freezing. I can't help but smile when I see the expression on some peoples faces when they pass by Ninefields, bundled up in layers of clothing, to see us larking around in the snow quite oblivious of the sub-zero temperatures!
First Line of Defence
The most obvious advantage we have is our winter coat, which can start growing in around late August in some areas. As the days shorten, the "hair factor" kicks in. Even in quite mild autumn weather, the shorter days and a couple of cold fronts coming through are enough remind horses and ponies to start to don their winter woollies.
Our winter coat differs from the summer one in that the hairs are longer and coarser. We are able to fluff up our coat, the individual hairs standing out, rather than laying flat against the skin, trapping air close to the body and thereby insulating us from the cold. The additional grease which accumulates in this thicker coat, especially if we are turned out enough, gives extra insulation.
Our Main Weapon Is the kind of food we eat and the way in which we digest it. Horses are grazing animals that do best if there is a small amount of food constantly being processed by the digestive system (remember the old saying "feed little and often!") Food which is rich in fibre is the best because, as the gut digests the fibre in the diet, heat is generated, contributing to our body warmth, even in freezing temperatures. One of the most natural ways to help us keep warm in the winter is to allow ad lib access to good quality hay.
Our Worst Enemy The wind. It chills us by blowing surface heat away from our bodies as quickly as it can be generated. Winds that are strong enough to ruffle winter coats leave us even colder by sapping the heat reserves normally trapped under thick hair layers. Combine such a wind with moisture in one form or another, and the chilling effects are even more drastic.
When we can, we stand with our rumps to the wind, using our tails to block the gusts. (Please bear this in mind when you want to pull our tails!) This natural protection is effective enough for unclipped horses, but a windbreak, such as a field shelter or a stand of evergreen trees, gives the best protection. Fully clipped horses require rugging in cool, windy weather, starting at about 50 degrees Fahrenheit.
Guidelines
If you are responsible for caring for a horse who has been clipped, follow these guidelines (Temperatures are in Fahrenheit.) If the horse or pony has a full coat, subtract 10 degrees from recommendation (for example, you'd put on a turnout sheet at 50 degrees, not 60). And, clipped or not, for turnout on days that are sunny and calm, the rugs chosen should be as if the temperature were ten degrees higher.
60-65 -- Turnout sheet
50-60 -- Sheet over lightweight liner
40-50 -- Mid weight insulated turnout rug, or turnout sheet over stable blanket
30-40 -- Heavy turnout rug, mid weight rug over stable sheet or fleece liner, or turnout sheet over stable blanket plus liner
20-30 -- Heavy rug over fleece liner, or medium rug over quilted liner or stable blanket
Below 20 -- Heavy rug over quilted liner or stable blanket, or mid weight rug over quilted liner or stable blanket plus fleece.
Too chilly? Too warm? Here's how to tell. Not warm enough: Ears cool to your touch, exposed hair coat stands on end, body tense (for instance, he stands stiffly without cocking a leg), shivering, tail clamped.
Too warm: Restlessness, sweating under the rug/blanket. To check, put your bare hand between the innermost layer and the coat -- and feel all the way back to the rib cage. The shoulder area near the binding, where dirt and dander accumulate first, tends to feel warm and sticky even when the rest of the body isn't. Important: Even if temperature and conditions don't change, your horse needs you to remove and reset the rug(s) at least once a day; twice is better. This is also your chance to check for rubs and sores that can result from even the best-fitting clothing, especially if dirt or shavings get lodged underneath. And if the rug goes askew during the day, don't straighten it by tugging -- that hurts! Instead, undo straps and fasteners (always from the back to the front), lift up the rear portion of the rug/blanket(s) and fold forward to the withers, then lift it completely clear from the back and put it down again in the correct position.
